Deck 4: Genes and Their Evolution: Population Genetics

Question 1

When individuals of the same species are reproductively isolated, genetic differences may accumulate in sufficient number so that new species could emerge.Such an event would be an example of:

A)microevolution.
B)the founder effect.
C)equilibrium.
D)macroevolution.

Answer 1

macroevolution.

Question 2

Over a period of two generations, the frequency of green dung beetles in a population shifts from 75% to 71% while the frequency of brown dung beetles within this population shifts from 25% to 29%.This is an example of:

A)minievolution.
B)microevolution.
C)millievolution.
D)nanoevolution.

Answer 2

microevolution.

Question 3

Evolution can best be defined as:

A)the appearance of a new species.
B)a change in allele frequencies in a breeding population over time.
C)changes in the DNA of an individual over his or her lifetime.
D)a process that occurs only over extremely long periods of time.

Answer 3

a change in allele frequencies in a breeding population over time.

Question 4

The ABO and MN blood-type frequencies of the Dunkers differ significantly from those of current American and German populations due to:

A)genetic drift.
B)natural selection.
C)gene flow.
D)mutation.

Question 5

Malaria is caused by:

A)bites from infected mosquitoes.
B)a genetic mutation.
C)drinking bad water.
D)eating spoiled food.

Question 6

In certain species of nonhuman primates there are groups where only one dominant female has access to mates.The other females must wait until the opportunity to mate presents itself.This will have direct impacts on "fitness," influencing which of the following?

A)reproductive success
B)aggressiveness
C)strength
D)age at death

Question 7

Which of the following is NOT a genetic disorder that decreases susceptibility to malaria?

A)G6PD deficiency (favism)
B)sickle-cell anemia
C)Huntington's chorea
D)thalassemia

Question 8

Transposable elements are DNA sequences that:

A)are not coded to produce proteins.
B)contain numerous point mutations.
C)occur only on the X and Y chromosomes.
D)can copy themselves into entirely new areas of the chromosomes.

Question 9

Which of the evolutionary forces is most likely to decrease variation between populations?

A)gene flow
B)the founder effect
C)mutation
D)natural selection

Question 10

A point mutation that does NOT result in a change to the amino acid coded for is said to be a _______ mutation.

A)spontaneous
B)synonymous
C)selective
D)stabilizing

Question 11

The physical location of a gene within the genome is called the:

A)chromosome.
B)nucleus.
C)address.
D)locus.

Question 12

While conducting research with a small population in South America you note that an overwhelming majority of individuals exhibit signs of a specific genetic abnormality.This is most likely the result of:

A)natural selection.
B)the founder effect.
C)extinction.
D)gene flow.

Question 13

Together, all of the alleles contained within a group of interbreeding individuals are known as a:

A)gene pool.
B)population.
C)clinal distribution.
D)polymorphism.

Question 14

Another name for the evolutionary force called gene flow is:

A)the "founder effect."
B)"disruptive selection."
C)"admixture."
D)"transposition."

Question 15

Mutations in DNA found in which cells are most likely to have significant evolutionary consequences?

A)sex cells (gametes)
B)red blood cells
C)skin pigment cells
D)brain cells

Question 16

The southern migration of which African people may have led to a significant increase in the incidence of malaria?

A)Masai
B)Turkana
C)Efe
D)Bantu

Question 17

The type of selection that favored progressively larger brain size in human evolution is _______ selection.

A)natural
B)directional
C)stabilizing
D)disruptive

Question 18

The clinal decrease in type B blood from East Asia to Western Europe is probably the result of:

A)the founder effect.
B)stabilizing selection.
C)mutation.
D)gene flow.

Question 19

Australian aborigines are an endogamous society.This means that marriage and reproduction take place within the group, leading to:

A)increased genetic diversity through genetic drift.
B)migration without gene flow.
C)more genetic diversity than would be observed in an exogamous society.
D)decreased genetic diversity due to a lack of admixture.

Question 20

Hardy-Weinberg equilibrium assumes:

A)strong selection pressure on the trait(s) being studied.
B)a significant mutation rate from generation to generation.
C)gene flow that is equal both into and out of the population.
D)no gene flow, mutation, or natural selection.

Question 21

Studies of Galapagos finches have found that at certain points in time all finches on the island have either wide beaks or sharp narrow beaks.The type of evolution that leads to this phenotype distribution is _______ selection.

A)directional
B)natural
C)disruptive
D)stabilizing

Question 22

A study of Galapagos finches after a long period of drought found that all species of finch on one of the islands had wide beaks well adapted to breaking open seeds.The type of evolution that leads to this phenotype distribution is _______ selection.

A)directional
B)natural
C)disruptive
D)stabilizing

Question 23

Patrilocal societies are expected to display:

A)greater mtDNA diversity than Y chromosome diversity.
B)roughly equivalent mtDNA and Y chromosome diversity.
C)greater Y chromosome diversity than mtDNA diversity.
D)no strong correlation between societal structure and genetic diversity.

Question 24

Fitness trade-off refers to selection favoring which genotype?

A)homozygous dominant
B)homozygous recessive
C)heterozygous
D)No genotype is favored.

Question 25

The best-documented case of industrial melanism involves:

A)Galápagos finches.
B)dung beetles.
C)monarch butterflies.
D)peppered moths.

Question 26

Frameshift mutations are more likely to have an impact at the phenotypic level because they:

A)are the result of a change in a single nucleotide.
B)are the result of exposure to radiation.
C)produce a protein having no function.
D)are mobile pieces of DNA.

Question 27

You are reading a scientific article about cheetahs that have stripes instead of spots.The article refers to this as a genetic mutation.Though you see they have no negative impact on the cheetahs' fitness, the stripes are nevertheless considered a genetic mutation because mutations:

A)can result in an evolutionary advantage.
B)can result in an evolutionary disadvantage.
C)may have no effect on the phenotype.
D)all of the above

Question 28

The absence of the A and B alleles in Native American populations is a result of:

A)natural selection.
B)gene flow.
C)the founder effect.
D)mutation.

Question 29

What effect does natural selection have on population variation?

A)It increases variation.
B)It decreases variation.
C)It both increases and decreases variation.
D)It does not affect variation.

Question 30

A genetic study conducted over multiple generations found that the frequency of genotypes in the first generation were AA: 0.36, Aa: 0.48, aa: 0.16.In the second generation, genotype frequencies shifted to AA: 0.16, Aa: 0.48, aa: 0.36.According to the Hardy-Weinberg equilibrium, we can assume:

A)random mating has altered gene frequencies.
B)gene flow has possibly shifted the gene frequencies.
C)mating in this population must be nonrandom mating.
D)both b.and c.

Question 31

The evolution of the modern horse with a single hoof on each limb from a dog-sized ancestral species with multiple digits is an example of:

A)macroevolution.
B)stabilizing selection.
C)disruptive selection.
D)microevolution.

Question 32

Why is the incidence of sickle-cell anemia an excellent example of a "balanced polymorphism," in which two or more alleles are maintained by natural selection in a population?

Question 33

In a classroom taste test for PTC the genotype frequency was determined to be P = 0.35 and Q = 0.65.After applying the Hardy-Weinberg equation, the percentage of genotypes was found to be as follows:

A)p2 = 0.12; 2pq = 0.46; q2 = 0.42.
B)p2 = 0.35; 2pq = 0.00; q2 = 0.65.
C)p2 = 0.12; 2pq = 0.65; q2 = 0.23.
D)p2 = 0.20; 2pq = 0.20; q2 = 0.60.

Question 34

What is a polymorphic trait? Provide two examples of polymorphic traits in modern humans, and give one example of a monomorphic trait.

Question 35

A random change in allele frequencies over time is known as:

A)genetic drift.
B)gene flow.
C)admixture.
D)gene migration.

Question 36

An individual who displays the disease sickle-cell anemia must have inherited the deleterious allele from both phenotypically normal parents.This individual is therefore:

A)homozygous, with two dominant alleles.
B)homozygous, with two recessive alleles.
C)heterozygous, with one dominant and one recessive allele.
D)haplozygous.

Question 37

Familial hypercholesterolemia, an autosomal dominant disease, is five times more frequent in the Afrikaner population of South Africa than in the original population of Europe from which the ancestors to the Afrikaners immigrated.This represents an example of:

A)natural selection.
B)bottleneck.
C)the founder effect.
D)kin selection.

Question 38

Spontaneous mutation is the result of:

A)unknown causes.
B)x-rays.
C)toxic chemicals.
D)UV radiation.

Question 39

A genetic study conducted over two generations found that the frequencies of genotypes in the first generation were AA: 0.36, Aa: 0.48, aa: 0.16.In the second generation, genotype frequencies remained the same.According to the Hardy-Weinberg equilibrium, we can assume:

A)negative assortative mating has maintained gene frequencies.
B)mutations have likely occurred, resulting in the same frequency.
C)mating in this population is random.
D)the population is small and we cannot detect change.

Question 40

The mutation known as trisomy 21, in which an extra copy of chromosome 21 is present, is more commonly known as _______ syndrome.

A)Turner
B)Down
C)Klinefelter's
D)Williams

Question 41

Why is a frameshift mutation far more likely to lead to a defective protein than a point mutation?

Question 42

Why is the peppered moth an excellent example of directional selection?

Question 43

Explain how the founder effect can lead to a descendent population that differs greatly from its parent population over a relatively short period of time.